America in the 1930s, and gangster George Kelly (Charles Bronson), who likes to be known as Machine Gun Kelly for his habit of carrying the weapon, is staging a bank robbery with his gang. In the process, he murders one of the security guards in a hail of bullets but makes a clean getaway thanks to canny forward planning which sees him switch cars, and dump all evidence of the crime. He meets up with his girlfriend, Flo (Susan Cabot), and they make it through a police checkpoint without arousing suspicion, yet it's not the police Kelly should be worrying about: the members of his own gang are restless and greedy...

Based loosely on a real life 1930s gangster, this crime thriller was scripted by R. Wright Campbell and was one of the films that got director and producer Roger Corman noticed in circles wider than those belonging to drive-in movie fans. Using simple but effective psychology, the portrait of Kelly is given depth without sacrificing the action or the brutality of his adventures, showing him to be cowardly and under the thumb of the trashy Flo, who eggs him on to greater acts of lawbreaking. Neither of them are doing it for the money so much as doing it for the feeling of power it gives them.

That power extends to Kelly keeping the stolen cash from his fellow gang members, raising their ire. One, a gas station attendant, has to threaten the gangster with opening the cage of a wild cat he has in his makeshift zoo, but ends up being mauled by the creature himself when Kelly turns the tables on him. Another, Howie (Jack Lambert), makes no secret of the grudge he holds against the self-appointed leader, and pulls a knife on him - which is countered with a pistol. Kelly is very fond of his weaponry, especially his Tommy Gun, and makes proud boasts about how quickly he can assemble it, even blindfolded (a trick which never comes in handy, it has to be said).

Examples of psychology sketched in with economy include Kelly's phobia about death, which extends to all symbols that might herald his demise. When he sees a coffin crossing his path during a subsequent bank robbery, he freezes, thereby messing up his own plans, and causing the death of one of the gang. Even a skull and crossbones tattoo gives him the shivers. Bronson is ideal in his role, getting to grips with the character's readily exhibited violent side (he slaps just about everyone in the cast) and showing up his pathetic-but-dangerous weaknesses with ease. Cabot is an excellent match for him, sly and seductive, but with a heart as cold as ice.

There is no one in the cast to sympathise with, not Flo's brothel-keeping parents or the ineffectual hangers-on who follow Kelly's orders, until the crime which Flo hopes will put Kelly's name up amongst the big league baddies emerges. They kidnap a little girl and her nurse (Barboura Morris) with the hope of securing a ransom from the girl's rich father, but, naturally, they're setting themselves up for a fall. The more the kidnapping draws on, the closer the police get to the gang's hideout, but it doesn't end in the bloody demise for all of them that is traditional - Kelly's weaknesses get the better of him; he's really no better than a big kid, a bully who has taken things too far. Consistently interesting, with a memorably despicable lead character, Machine Gun Kelly works entertainingly well on its low budget. Music by Gerald Fried.